Atkinson et al. (Applied Physics Letters, 93, 101908 (2008)) describes the growth of nanostructures on a pre-structured surface. A local arrangement of single and pairs of InAs quantum dots at ex situ defined nanometer sized holes during growth is demonstrated using a GaAs(001) substrate surface which is patterned by electron-beam photolithography and dry etching.
So far, the step of pre-patterning the surface to obtain local arrangement of nanostructures is done using complex patterning techniques like electron beam lithography, focussed ion beam etching, ion implantation and the like. The direct surface patterning may cause crystal damages and defects that may have negative impacts on the quality and performance of nanostructures made thereon. Long-range impact of the patterning along the surface normal of a substrate is useful as it enables the separation of the nanostructures from patterning-induced defects.